JP5337577B2 - Container manufacturing method and blow mold - Google Patents

Description

The present invention relates to a blow molding die used in the blow molding preparation and container vessel for producing containers by blow molding.

  In recent years, for example, regarding the production of a synthetic resin container by biaxial stretch blow molding, productivity has been improved by means such as raising the mold temperature or raising the mechanical cycle (molding cycle).

JP-A-5-345350

  However, since the coefficient of motion solid friction generally tends to increase with an increase in the mold surface temperature, increasing the mold temperature increases the frictional force and tends to cause defective release of the container from the mold. If the container is provided with a reduced pressure absorption panel, the panel is pulled toward the mold side when the mold is released, and panel swelling (a phenomenon in which the reduced pressure absorption panel protrudes outward from the container) is likely to occur.

  As a countermeasure, it is conceivable that the vacuum absorbing panel is greatly curved inward of the container. However, if the vacuum absorbing panel is made too deep, an undercut at the time of mold release becomes large, which causes a scratch.

The present invention has been made in view of the above-mentioned circumstances, and the object thereof is to improve the releasability of the container after blow molding from the mold, and at the same time has high added value to the container after molding. It is to provide a manufacturing method and a blow molding mold vessel capable of causing.

  In order to achieve the above object, a method for producing a container according to the present invention is a method for producing a container comprising a reduced pressure absorption panel and a container having a protrusion provided on the reduced pressure absorption panel by blow molding. An air hole for forming the protrusion is provided in the mold, the air hole is communicated with the outside of the mold, and air is supplied from the air hole into the mold after the blowing process.

  Here, it is desirable to provide a plurality of the air holes so that the protrusions are arranged to display at least one of letters, numbers, symbols, patterns or figures.

  Further, the mold may include a nest for forming the reduced pressure absorption panel, and the air hole may be constituted by a through hole provided in the nest.

  In order to achieve the above object, a blow molding die according to the present invention is a blow molding die used for blow molding of a container provided with a reduced pressure absorption panel and provided with protrusions on the reduced pressure absorption panel. An air hole for forming the protrusion is provided, and the air hole communicates with the outside of the mold.

  Here, in the blow mold, a plurality of the air holes may be provided so that the protrusions are arranged to display at least one of letters, numbers, symbols, patterns, or figures. 5).

  The blow molding die may include a nest for forming the reduced pressure absorption panel, and the air hole may be a through hole provided in the nest.

In the invention which concerns on Claims 1-6 , the release property from the metal mold | die of the container after blow molding can be made favorable, and manufacture of the container which can give a high added value to the container after shaping | molding simultaneously A method and blow mold are obtained.

  In other words, in the inventions according to claims 1 and 4, the releasability of the container can be improved by supplying air from the air hole to the container after the blowing process accommodated in the mold.

  In addition, in the inventions according to claims 2 and 5, it is possible to give added value to the container by utilizing the protrusion formed by entering the air hole during the blowing process.

  Moreover, in the inventions according to claims 3 and 6, the arrangement of the protrusions formed on the container can be easily changed by exchanging the insert.

It is a longitudinal cross-sectional view which shows schematically the structure of the metal mold | die for blow molding used for the manufacturing method of the container which concerns on one embodiment of this invention. It is a top view which shows roughly the arrangement structure of the insert of the said metal mold | die for blow molding. (A) And (B) is the front view and longitudinal cross-sectional view which show schematically the structure of the insert of the said metal mold | die for blow molding, (C) is the sectional view on the AA line of (A). It is a partial expanded longitudinal cross-sectional view which shows schematically the structure of the principal part of the said metal mold | die for blow molding. It is a front view which shows roughly the structure of the blow molding container which concerns on one embodiment of this invention. It is a front view which shows roughly the structure of the modification of the said blow molding container. It is a front view which shows roughly the structure of the other modification of the said blow molding container. It is a front view which shows roughly the structure of the other modification of the said blow molding container.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a longitudinal sectional view schematically showing the structure of a blow molding die used in the container manufacturing method according to an embodiment of the present invention, and FIG. 2 is a diagram showing the nesting of the blow molding die. FIG. 3A and FIG. 3B are a front view and a longitudinal sectional view schematically showing the structure of the insert of the blow molding die, and FIG. 3C is a diagram. FIG. 4 is a partially enlarged longitudinal sectional view schematically showing the structure of the main part of the blow molding die, and FIG. 5 is a blow according to an embodiment of the present invention. FIG. 6 to FIG. 8 are front views schematically showing configurations of modified examples of the blow molded container, respectively.

  First, a container manufacturing method (hereinafter abbreviated as “manufacturing method”) and a blow molding die (hereinafter abbreviated as “mold”) according to this embodiment are blow molded containers (hereinafter abbreviated as “mold”). , Abbreviated as “container”).

  Therefore, first, the configuration of the container 1 will be described. The container 1 is made of a thermoplastic resin (for example, polyethylene terephthalate) and is a bottomed substantially cylindrical member. As shown in FIG. A shoulder portion 3, a trunk portion 4, and a bottom portion (heel portion) 5. The body 4 is provided with an upper body 4b and a lower body 4c on top and bottom with a constricted part 4a formed substantially in the center of the body 4, and the lower body 4c has six decompressions. Absorption panels 6 are provided at intervals in the circumferential direction.

  The reduced pressure absorption panel 6 is deformed when the container 1 is cooled after filling the contents and its internal pressure is reduced (depressurized), thereby exhibiting a reduced pressure absorption function that suppresses deformation of other parts, Each decompression absorption panel 6 is formed with a plurality of protrusions 7. These protrusions 7 are arranged so as to be braille, and each protrusion 7 is substantially circular in a front view and has a diameter of 2.3 to 3.0 mm (2.7 mm in the present embodiment).

  FIGS. 3A and 5 show an example in which the protrusions 7 are arranged in each decompression absorption panel 6 so as to be read as “Mirinfu”. Therefore, the container 1 of the present embodiment is filled with mirin-like seasoning so that it can be distinguished from another container in which the present mirin is accommodated by the braille formed by the protrusions 7.

  On the other hand, as shown in FIG. 1, the mold according to the present embodiment includes a mold main body 11 and a plurality (six in this embodiment) of nests 12 mounted in the mold main body 11. The bottom mold 13 is provided.

  The insert 12 is used to form the six vacuum absorption panels 6 of the container 1, and as understood from the planar arrangement schematically shown in FIG. Six nests 12 are arranged at intervals in the direction.

  Each nest 12 has a plurality of through holes 14 serving as air holes for forming the protrusions 7 of the container 1 as shown in FIGS. 3 (A) and 3 (B). The insert 12 extends so as to penetrate from the front surface 12a side to the back surface 12b side. Here, the through hole 14 has a circular cross section, has a uniform diameter from one end (front surface 12a) side to the other end (back surface 12b) side, and has a diameter of 2.3 to 3.0 mm (in this embodiment). 2.7 mm).

  Further, as shown in FIGS. 3A to 3C, each insert 12 is provided with two screw holes 15 that are recessed from the back to the front. As shown in FIG. 1, each insert 12 is fixed to the mold body 11 by a bolt 16 screwed into each screw hole 15 so that the front surface 12 a faces the inside of the mold body 11. In the fixed state, some gaps 17 (for example, 0.1 to 2.5 mm, preferably 0.7 to 2.1 mm) are formed between the back surface 12 b of the insert 12 and the mold body 11. (See FIG. 1).

  On the other hand, as shown in FIG. 1, the mold body 11 is provided with a communication path 18 that communicates with the gap 17 and communicates with the outside of the mold body 11. Therefore, the through hole 14 of the insert 12 fixed to the mold body 11 communicates with the outside of the mold body 11 through the gap 17 and the communication path 18.

  Next, the manufacturing method of this embodiment is demonstrated.

  (1) First, a bottomed tubular (test tubular) preform (parison) made of a thermoplastic resin (for example, polyethylene terephthalate) is formed and heated at an appropriate stretching temperature (for example, 80 to 130 ° C.).

  (2) Subsequently, the preform is housed in a mold (a cavity formed by the mold body 11, the insert 12, and the bottom mold 13).

  (3) Thereafter, blow air is supplied from the mouth of the preform to stretch the preform in the radial direction, and heat setting is also performed by heating to an appropriate temperature (for example, 130 to 180 ° C.). In addition to the stretching in the radial direction of the preform, the preform may be stretched in the axial direction (biaxial stretching) using a stretching rod.

  By this blowing step (3), the preform becomes a container 1 having a predetermined shape along the inner surface of the mold, and the portion of the container 1 corresponding to the through hole 14 of the insert 12 is shown in FIG. Thus, it will be in the state which entered the through-hole 14, and, thereby, the protrusion 7 (refer FIG. 5) will be formed.

  (4) The air in (3) is blown into the container 1 and simultaneously the air is circulated by discharging the air from the container 1 to cool the container 1.

  (5) Finally, the container 1 is taken out from the mold. When the mold is released (from the start to the end of the mold release), air is passed from the outside of the mold body 11 to the communication path 18. Supply. And since this air passes through the clearance gap 17 and reaches each through-hole 14, air will enter between the container 1 and the insert 12, and the mold release of the container 1 will be performed smoothly.

  The container 1 shown in FIG. 5 is obtained by the above steps (1) to (5).

  According to the manufacturing method and the mold of the present embodiment, the releasability of the container 1 can be improved by supplying air from the through hole 14 to the container 1 after the blowing process accommodated in the mold. Moreover, Braille can be comprised by the processus | protrusion 7 which penetrates and forms the through-hole 14 at the time of a blow process, and can give the container 1 an added value.

  Thus, the through holes 14 for providing the protrusions 7 are necessary for improving the releasability of the container 1, and if the number is too small, the effect of improving the releasability is achieved. Not enough.

  Here, the inventors set the diameter of the through-hole 14 to 1.7 mm, 2.3 mm, and 3.5 mm in addition to 2.7 mm, and make the diameter from one end to the other end uniform. Rather, as a result of performing the test by variously changing the shape of the through hole 14 such as changing the diameter at one end side and the other end side with the intermediate portion as a boundary, as shown in this embodiment, one end (front surface) 12a side) to the other end (back surface 12b side) is uniform in diameter, and when the through hole 14 having a diameter of 2.3 to 3.0 mm is used, the Braille formed by the protrusions 7 is easy to read. I have confirmed.

  The present invention is not limited to this embodiment, and can be implemented with various modifications. Therefore, the modified example will be described below.

  The container 1 is not limited to the substantially cylindrical shape described above, and may be a substantially rectangular tube shape, for example.

  The protrusion 7 may be configured to display something other than Braille. That is, the protrusions 7 are arranged in various patterns (for example, see FIG. 6), characters other than Braille (for example, alphabets: see FIG. 7), numbers (for example, Arabic numerals), symbols (symbols), figures (for example, see FIG. 8). Etc. may be displayed. Accordingly, the protrusion 7 is arranged so as to display the company name, product name, etc. on the reduced pressure absorption panel 6 and the weight and physical properties (bottle physical properties) of the container 1 can be identified according to the weight and physical properties. The arrangement of the protrusions 7 can be varied. In this way, when the projection 7 displays something other than Braille, the shape and size of the projection 7 can be variously changed. Further, the protrusions 7 may be arranged side by side to display not only characters (including Braille), numbers, symbols, patterns, and figures but also combinations thereof.

  And although it is preferable that the arrangement | positioning of the processus | protrusion 7 in each decompression absorption panel 6 is unified in the point of uniformity, you may make it different.

  Further, the configuration of the through hole 14 can be variously changed regardless of whether or not the braille is displayed by the protrusion 7. That is, in the present embodiment, the through hole 14 forming the air hole has a uniform diameter from one end to the other end, is opened toward the front surface 12a, and the size of the opening is 2.3 to 3.0 mm. However, for example, the diameter of the through hole 14 can be made different between the one end side and the other end side with respect to the intermediate portion.

  The nests 12 are provided so as to correspond to the reduced pressure absorption panel 6, and the number thereof is not limited to six.

  Further, the insert 12 may not be provided. In this case, an air hole for forming the protrusion 7 may be provided in the mold body 11 and the air hole may be communicated with the communication path 18.

  In the step (5), the air supply from the outside of the mold body 11 to the communication path 18 may be performed before the start of mold release or after the start. However, it is only necessary to prevent panel swelling.

  Needless to say, the plurality of modifications described above may be combined as appropriate.

1 Container 6 Vacuum Absorption Panel 7 Protrusion 12 Nesting 14 Through Hole (Air Hole)

Claims (6)

  A manufacturing method of a container comprising a vacuum absorbing panel, wherein a container having a protrusion provided on the vacuum absorbing panel is manufactured by blow molding, wherein an air hole for forming the protrusion is provided in a mold, and the air hole is formed A method for manufacturing a container that communicates with the outside of the mold and supplies air into the mold from the air hole after the blowing step.   The container manufacturing method according to claim 1, wherein a plurality of the air holes are provided so that at least one of a letter, a number, a symbol, a pattern, or a figure is displayed side by side with the protrusions.   The manufacturing method of the container according to claim 1 or 2, wherein the mold includes a nest for forming the reduced pressure absorption panel, and the air hole is configured by a through hole provided in the nest.   A blow-molding die for use in blow-molding a container provided with a reduced-pressure absorption panel and provided with a protrusion on the reduced-pressure absorption panel, wherein an air hole for forming the protrusion is provided, and the air hole is a metal mold Blow molding mold configured to communicate with the outside of the mold.   The blow mold according to claim 4, wherein a plurality of the air holes are provided so that at least one of a letter, a number, a symbol, a pattern, or a figure is displayed side by side with the protrusions.   The blow molding die according to claim 4 or 5, further comprising a nest for forming the reduced pressure absorption panel, wherein the air hole is a through hole provided in the nest.

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